Where a desk-top electronic calculator or computer carries out a particular calculation such as a time data calculation, angle data calculation, a mis-entry correction of input data has to be done by a different correcting manner from the conventional correcting manner, since the input data, such as time, comprises different dimensions of data such as hour, minute and second, and each of which is also given by different number systems, such as a bidecimal notation, and a sixty-base notation. For instance, in time data calculation the following input data clearings or corrections are required:
(1) With entered data of 12 o'clock (hours) 34 minutes 56 seconds, time in seconds; that is, 56 seconds must be corrected to 45 seconds;
(2) With entered data of 12 o'clock (hours) 34 minutes 56 seconds, the whole input data must be cleared or erased;
(3) Where an augend 12 o'clock (hours) 34 minutes and addend 11 o'clock 42 minutes are added, if the augent 12 o'clock 34 minutes is entered, and an operation instruction is present, and then addend 11 o'clock 10 minutes is mis-entered, only 10 minutes in the addend must be corrected to 42 minutes; and
(4) With the augend and addend entered as (3), the whole input data must be cleared or erased.
The primary object of the present invention is therefore to provide a system for clearing desired data by the depression of only one clear key.
Another object of the present invention is to provide a system for clearing the specified data of a series of input data by depressing the clear key.